Helicos BioSciences Corporation (NASDAQ: HLCS) announced today that it has filed a lawsuit against Pacific Biosciences of California, Inc. for patent infringement. The lawsuit, filed in the United States District Court for the District of Delaware, accuses PacBio of infringing four patents and seeks injunctive relief and monetary damages. “Helicos was the first to invent and market single molecule sequencing technology and has established a comprehensive patent estate with the earliest priority dates in the field” said Ronald A. Lowy, President and CEO of Helicos. “Pacific Biosciences is a newcomer to the single molecule sequencing market and has introduced technology and products that infringe our patents. We have full confidence that our patents in this lawsuit, which have expiration dates that extend well into the future up to 2028, are valid, enforceable and are infringed by Pacific Biosciences. We plan to vigorously defend our intellectual property rights and owe it to our stockholders and our customers to protect the technology investments we have made throughout the years.” In the lawsuit, Helicos claims that Pacific Biosciences incorporated the patented sequencing-by-synthesis technology into its Single Molecule Real Time (SMRT™) systems and products. The patents cover sequencing-by-synthesis methods using labeled nucleotides. The nucleotides are labeled with detectable markers, such as fluorescent markers, that enable determination of each nucleotide incorporated into the DNA strand being extended by the polymerase. The patents describe processes that involve, for example, identifying each new nucleotide by observing its detectable label and neutralizing or removing the label before addition of the next nucleotide. The 3’ hydroxyl groups of the nucleotides are free, permitting the repeated addition of nucleotides over the course of a sequencing-by-synthesis process. Helicos believes this fundamental, patented sequencing-by-synthesis technology underlies Pacific Biosciences’ SMRT™ platform, in which labeled nucleotides with free 3’ hydroxyl groups are detected and incorporated in a continuous sequencing-by-synthesis process.